scholarly journals Test of QCD at large Q2 with exclusive hadronic processes

2014 ◽  
Vol 31 ◽  
pp. 1460304
Author(s):  
Chengping Shen ◽  

My report consists of two parts: (1). Using samples of 102 million ϒ(1S) and 158 million ϒ(2S) events at Belle, we study 17 exclusive hadronic decays of these two bottomonium resonances to some Vector-Pseudoscalar (VP), Vector-Tensor (VT) and Axial-vector-Pseudoscalar (AP) processes and their final states. Branching fractions are measured for all the processes. The ratios of the branching fractions of ϒ(2S) and ϒ(1S) decays into the same final state are used to test a perturbative QCD (pQCD) prediction for OZI-suppressed bottomonium decays. (2). Using data samples of 89 fb-1, 703 fb-1, and 121 fb-1 collected at center-of-mass (CMS) energies 10.52, 10.58, and 10.876 GeV, respectively, we measure the cross sections of e+e- → ωπ0, [Formula: see text], and [Formula: see text]. The energy dependence of the cross sections is presented.

2014 ◽  
Vol 35 ◽  
pp. 1460440
Author(s):  
ALBERTO LUSIANI

We report recent measurements on τ leptons obtained by the BABAR collaboration using the entire recorded sample of electron-positron collisions at and around the Υ(4S) (about 470fb-1). The events were recorded at the PEP-II asymmetric collider at the SLAC National Accelerator Laboratory. The measurements include high multiplicity τ decay branching fractions with 3 or 5 charged particles in the final state, a search for the second class current the τ decay τ → πη′ν, τ branching fractions into final states containing two KS mesons, [Formula: see text], with h = π, K, and preliminary measurements of hadronic spectra of τ decays with three hadrons (τ- → h-h+h-ντ decays, where h = π, K). The results improve the experimental knowledge of the τ lepton properties and can be used to improve the precision tests of the Standard Model.


2020 ◽  
Vol 15 ◽  
pp. 249
Author(s):  
V. Ch. Chasioti ◽  
T. S. Kosmas ◽  
P. Divari

Inelastic neutrino-nucleus reaction cross sections are studied focusing on the neutral current processes. Particularly, we investigate the angular and initial neutrino-energy dependence of the differential and integrated cross sections for low and intermediate energies of the incoming neutrino (or antineutrino). Contributions coming from both, the vector and axial-vector components of the corresponding hadronic currents have been included. The initial and final state nuclear wave-functions have been calculated in the context of the Quasi-particle Random Phase Approximation (QRPA) tested on the reproducibility of the low-lying energy spectrum (up to about 5 MeV) of the studied nuclei. The results presented here refer to the nuclear isotopes 16O and 98Mo. As it is well known, O plays a significant role in supernova evolution phenomena and Mo is used as a target in the MOON neutrino experiment at Japan.


2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
◽  
A. Tumasyan ◽  
W. Adam ◽  
J. W. Andrejkovic ◽  
T. Bergauer ◽  
...  

Abstract A search for a heavy Higgs boson H decaying into the observed Higgs boson h with a mass of 125 GeV and another Higgs boson hS is presented. The h and hS bosons are required to decay into a pair of tau leptons and a pair of b quarks, respectively. The search uses a sample of proton-proton collisions collected with the CMS detector at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 137 fb−1. Mass ranges of 240–3000 GeV for mH and 60–2800 GeV for $$ {m}_{{\mathrm{h}}_{\mathrm{S}}} $$ m h S are explored in the search. No signal has been observed. Model independent 95% confidence level upper limits on the product of the production cross section and the branching fractions of the signal process are set with a sensitivity ranging from 125 fb (for mH = 240 GeV) to 2.7 fb (for mH = 1000 GeV). These limits are compared to maximally allowed products of the production cross section and the branching fractions of the signal process in the next-to-minimal supersymmetric extension of the standard model.


2005 ◽  
Vol 20 (16) ◽  
pp. 3701-3703
Author(s):  
Guang-Pei Chen

Using 57.2 pb-1 of data collected with the CLEO-c detector at the ψ(3770) resonance, we measure absolute branching fractions for three D0 and two D+ Cabibbo-allowed hadronic decay modes, and the cross section for [Formula: see text] at [Formula: see text].


2017 ◽  
Vol 12 (5) ◽  
Author(s):  
Hai-Bo Li

Abstract The study of hyperon decays at the Beijing Electron Spectrometer III (BESIII) is proposed to investigate the events of J/ψ decay into hyperon pairs, which provide a pristine experimental environment at the Beijing Electron–Positron Collider II. About 106–108 hyperons, i.e., Λ, Σ, Ξ, and Ω, will be produced in the J/ψ and ψ(2S) decays with the proposed data samples at BESIII. Based on these samples, the measurement sensitivity of the branching fractions of the hyperon decays is in the range of 10−5–10−8. In addition, with the known center-of-mass energy and “tag technique”, rare decays and decays with invisible final states can be probed.


2005 ◽  
Vol 20 (02n03) ◽  
pp. 661-663
Author(s):  
◽  
FRÉDÉRIC KAPUSTA

Heavy b and c quark production in γγ collisions has been measured through semileptonic decays with the DELPHI detector at LEPII. The measured cross-sections are compared to NLO perturbative QCD calculations. The cross-section for b production is found to exceed QCD predictions. The K-lepton double tagging, used for the first time in γγ physics confirms this excess.


2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Hossein Mehraban ◽  
Behnam Mohammadi

We study the contributions of theB→ψ(3770)K[ψ(3770)→DD̅],B→K*(1410)π[K*(1410)→Kπ], andB→X(3872)K[X(3872)→J/ψγ,ψ(2S)γ,DD-π,J/ψω,J/ψππ, andDD-*π]quasi-two-body decays. There are no existing previous measurements of the three-body branching fractions for three final states of theX(3872)→J/ψγ,ψ(2S)γ, andDD̅π, but several quasi-two-body modes that can decay to this final state have been seen.


2004 ◽  
Vol 19 (01) ◽  
pp. 1-17 ◽  
Author(s):  
HANNES JUNG

The basic ideas of kt-factorization and CCFM parton evolution is discussed. The unintegrated gluon densities, obtained from CCFM fits to the proton structure function data at HERA are used to predict hadronic final state cross-sections like jet production at HERA, but also comparisons with recent measurements of heavy quark production at the Tevatron are presented. Finally, the kt-factorization approach is applied to Higgs production at high energy hadron–hadron colliders and the transverse momentum spectrum of Higgs production at the LHC is calculated.


2006 ◽  
Vol 21 (27) ◽  
pp. 5503-5512 ◽  
Author(s):  
M. R. PENNINGTON

Dalitz analyses are introduced as the method for studying hadronic decays. An accurate description of hadron final states is critical not only to an understanding of the strong coupling regime of QCD, but also to the precision extraction of CKM matrix elements. The relation of such final state interactions to scattering processes is discussed.


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